public static string InsertNewCustomer(Customer customer)
        {
            if (customer == null)
            {
                throw new ArgumentNullException("Customer cannot be null");
            }

            using (var northwindEntities = new NorthwindEntities())
            {
                northwindEntities.Customers.Add(customer);
                northwindEntities.SaveChanges();
                return customer.CustomerID;
            }
        }
        public static void Main()
        {
            var testCustomer = new Customer
            {
                CustomerID = "aaa",
                CompanyName = "Telerik"
            };

            Console.WriteLine("Inserting a new Customer with Id {0} : ", testCustomer.CustomerID);
            Console.WriteLine(new string('-', 30));
            TestInsertingCustomer(testCustomer);
            Console.WriteLine();

            Console.WriteLine("Modifying Customer's Company {0} : ", testCustomer.CompanyName);
            Console.WriteLine(new string('-', 30));
            TestMoodifyingCustomer(testCustomer.CustomerID);
            Console.WriteLine();

            Console.WriteLine("Deleting Customer with Id {0} : ", testCustomer.CustomerID);
            Console.WriteLine(new string('-', 30));
            TestDeleteingCustomer(testCustomer.CustomerID);
            Console.WriteLine();

            var northwindDb = new NorthwindEntities();

            Console.WriteLine("Displaying Customers who shipped to Canada in 1997: ");
            Console.WriteLine(new string('-', 30));
            FindCustomersByOrdersYearAndCountry(northwindDb, 1997, "Canada");
            Console.WriteLine();

            Console.WriteLine("Displaying Customers who shipped to Canada in 1997 (with native SQL): ");
            Console.WriteLine(new string('-', 30));
            FindCustomersByOrdersYearAndCountryWithNativeSql(northwindDb, 1997, "Canada");
            Console.WriteLine();

            Console.WriteLine("Displaying Orders shipped to Rio de Janeiro between 15 and 20 years ago.");
            Console.WriteLine(new string('-', 30));
            FindSalesByRegionAndTimePeriod(northwindDb, "RJ", DateTime.Now.AddYears(-20), DateTime.Now.AddYears(-15));
            Console.WriteLine();
        }
        public static string AddCustomer(string customerId, string companyName, string contactName, string contactTitle,
            string address, string city, string region, string postalCode, string country, string phone, string fax)
        {
            var northwind = new NorthwindEntities();
            var customer = new Customer()
            {
                CustomerID = customerId,
                CompanyName = companyName,
                ContactName = contactName,
                ContactTitle = contactTitle,
                Address = address,
                City = city,
                Region = region,
                PostalCode = postalCode,
                Country = country,
                Phone = phone,
                Fax = fax,
            };

            northwind.Customers.Add(customer);
            northwind.SaveChanges();
            return customer.CustomerID;
        }
 /// <summary>
 /// Deprecated Method for adding a new object to the Customers EntitySet. Consider using the .Add method of the associated ObjectSet&lt;T&gt; property instead.
 /// </summary>
 public void AddToCustomers(Customer customer)
 {
     base.AddObject("Customers", customer);
 }
 /// <summary>
 /// Create a new Customer object.
 /// </summary>
 /// <param name="customerID">Initial value of the CustomerID property.</param>
 /// <param name="companyName">Initial value of the CompanyName property.</param>
 public static Customer CreateCustomer(global::System.String customerID, global::System.String companyName)
 {
     Customer customer = new Customer();
     customer.CustomerID = customerID;
     customer.CompanyName = companyName;
     return customer;
 }
        // task 2 - Create a DAO class with static methods which provide functionality for inserting, modifying and deleting customers. Write a testing class.
        private static void TestInsertingCustomer(Customer newCustomer)
        {
            var newId = CustomerModifier.InsertNewCustomer(newCustomer);

            Console.WriteLine("Added a new customer with id {0}", newId);
        }